The probe Voyager 1 travels far away in the universe
After many false alarms and postponements, finally the awaited moment has arrived. The NASA spacecraft Voyager 1 is officially the first human to enter interstellar space. The probe, which has switched off the 36th candle, is approximately 19 billion kilometers from the Sun.
The new data just published by Science reveal that Voyager 1 traveled for about a year in plasma and ionized gas that is present in the space between the stars. And Stone, the designer of the Institute of Technology in Pasadena, California said: “this is the first time that mankind is released outside the cradle of the solar system to explore the Galaxy”. Voyager 1 has passed then the so-called “bubble”, the region of charged particles surrounding the Sun, well beyond the orbits of the planets, entering a transition zone. According to NASA, Voyager 1 has crossed that border more or less on 25 August: this is the first time that the U.S. Space Agency announces transit historian even though in the past other experts had speculated that occurred. As early as last June the ship was supposed to be outside of the solar system, instead stood in an area not so far called “depletion heliosheath region”, in which it is still felt the solar magnetic field. The spacecraft is equipped with sensors that measure plasma density physically, so scientists have used a different method to figure out where it really was. A solar eruption in March 2012 provided the information required. The energy given off by the Sun to the Voyager 1 reached 13 months later, in April 2013, when the plasma surrounding the spacecraft began to vibrate noticeably. The swings were as a godsend for researchers, because it means that the spacecraft was immersed in the plasma 40 times more dense than they had met in the outer layer of the heliosphere. A density of this type is to be expected even in interstellar space. The signal emitted from Voyager is very weak: only 23 Watts, almost as much as a refrigerator light bulb.
It employs approximately 17 hours to reach Earth and, given its great distance, it gets reduced to a fraction of a billion watts: to receive it using a series of antennas that have a diameter ranging from 34 to 70 meters. Inside the space module there is a golden disk containing sounds and images of our land: a kind of message in a bottle tossed into the cosmic sea. The probe was launched as part of NASA’s Voyager on September 5, 1977 from Cape Canaveral along with its twin probe Voyager 2. The ships have already touched upon two planets, Jupiter and Saturn, and discovered sulphur volcanoes that had never been seen by other probes. In 1980 the twins of NASA passed near Saturn photographing rings. Today Voyager 2 is at 15.3 billion miles from Earth. The spacecraft travels at a speed of 17 kilometers per second, powered by a battery that will operate until 2025 when it should have reached a distance of more than 25 billion kilometers from our planet. The project will cost NASA about $ 5 million a year and it has already reached the figure of 988 million dollars in total.